Methods and devices for recording marks on a recording surface of an optical record carrier and optical record carriers therefor

ABSTRACT

The invention relates to methods, devices and carriers for forming marks and lands by applying a radiation beam to a recording surface of an optical record carrier. Recording strategies are proposed for recording information mainly for DVR-R (BD-R) formats. A sequence of portions  2, 4, 5  of a write irradiation period  3  is proposed.

The invention relates to an optical record carrier recording method forforming marks and lands by applying a radiation beam to a recordingsurface of an optical record carrier, the marks having a time length ofnT, where T represents the time length of one period of a referenceclock in a data signal and n represents a predetermined natural number,where the radiation beam for each mark to be recorded is first set to aintermediate power irradiation level, the intermediate power irradiationlevel being higher than bottom power irradiation level and lower thanwrite power irradiation level, where the intermediate power irradiationlevel is set in accordance with a time length of the preceding bottompower irradiation period.

The invention also relates to an optical record carrier recording methodfor forming marks and lands by applying a radiation beam to a recordingsurface of an optical record carrier, the marks having a time length ofnT, where T represents the time length of one period of a referenceclock in a data signal and n represents a predetermined natural numbersmaller than 3, where the radiation beam for each mark to be recorded isfirst set to a intermediate power irradiation level, the intermediatepower irradiation level being higher than bottom power irradiation leveland lower than write power irradiation level, where the intermediatepower irradiation level is set in accordance with a time length of thepreceding bottom power irradiation period.

The invention also relates to optical recording devices for carrying outsuch methods.

The invention also relates to optical carriers capable of having suchmethods applied to them.

A recording method of the kind set in the preamble is known from apatent application WO 01/86643. In a solution presented in the patentapplication a mark is formed by applying a radiation beam to a recordingsurface of an optical record carrier set to have an intermediate powerlevel after the bottom power level and before the write power level.Furthermore, a mark is formed by applying a radiation beam having writepower level and elevated power level to a recording surface of anoptical record carrier in the first and the second portion of the writepower irradiation period respectively. The preferred elevated powerlevel is set to be within the range from 1.05 to 1.15 times the writepower level and from 1.00 to 1.08 times the write power level for marksto be recorded having a time length of 3T and 4T respectively. Therecording method allows to reduce a jitter and is especially applicableto CD-R systems.

It is an object of an invention to provide a method of recording marksof the kind described in the opening paragraph which is better suitableto DVR-R (BD-R) format.

This object is achieved by a method as described in the preamble whichis characterized in that after the intermediate power irradiationperiod, the radiation beam for each mark to be recorded is set to thewrite power irradiation level during a first and a third portions of awrite irradiation period. Whereas the radiation beam for each mark to berecorded is set to an elevated write power level during a second portionof the write irradiation period. The elevated write power level ishigher than the write power level. Both the elevated write power leveland the duration of the second portion of the write irradiation periodare being set in accordance with a time length of a mark to be recorded.

This object is also achieved by a method as described in the preamblewhich is characterized in that after the intermediate power irradiationperiod, the radiation beam for each mark to be recorded is set to anelevated write power irradiation level during a first portion of a writeirradiation period. Whereas the radiation beam for each mark to berecorded is set to the write power level during a second portion of thewrite irradiation period. The elevated write power level is higher thanthe write power level. Both the elevated write power level and theduration of the first portion of the write irradiation period are beingset in accordance with a time length of the mark to be recorded.

A preferred version of the method according to the invention ischaracterized in that where n equals 2 the elevated write power level isset to be lower than 2.0 times the write power level. Where n equals 3,the elevated write power level is set to be lower than 1.7 times thewrite power level; where n equals 4, the elevated write power level isset to be lower than 1.5 times the write power level; and where n islarger than 4, the elevated write power level is set to be lower than1.4 times the write power level.

Another feature characterizing a preferred version of the methodaccording to the invention is that where the duration of the length of apreceding bottom power irradiation period is smaller than 2T, theintermediate power irradiation level is set to be lower than 0.5 timesthe write power level. The duration of the length of a preceding bottompower irradiation period is equal to 3T, the intermediate powerirradiation level is set to be within the range from 0.3 to 0.8 timesthe write power level; where the duration of the length of a precedingbottom power irradiation period is equal to 4T, the intermediate powerirradiation level is set to be within the range from 0.4 to 0.9 timesthe write power level; and where the duration of the length of apreceding bottom power irradiation period is greater than 4T, theintermediate power irradiation level is set to be greater than 0.5 timesthe write power level.

This object of an invention is also achieved by a method as described inthe preamble for marks having a time length of nT, where T representsthe time length of one period of a reference clock in a data signal andn represents a predetermined natural number smaller than 3, which ischaracterized in that after the intermediate power irradiation periodthe radiation beam for each mark to be recorded is set to the writepower irradiation level during a first portion of a write irradiationperiod. Whereas the radiation beam for each mark to be recorded is setto an elevated write power level during a second portion of the writeirradiation period and where the elevated write power level is higherthan the write power level.

It is a further object of the invention to provide an optical recordingdevice for carrying out the methods according to the invention. Thisobject is achieved by optical recording devices which have features asdescribed in claim 14 or claim 15 or claim 16.

It is a further object of the invention to provide an optical recordcarrier where the parameters for carrying out the methods according tothe invention are pre-recorded in the appropriate part of the opticalrecord carrier. This object is achieved by optical recording deviceswhich have features as described in claim 17.

Although the invention is explained by using a DVR-R (BD-R) system as anexample, it will be apparent to those skilled in the art that theinvention may be applied to alternative optical recording systems.

The objects, features and advantages of the invention well be apparentfrom the following, more specific description of embodiments of theinvention as illustrated in the accompanying drawings, wherein:

FIG. 1 shows a diagram of a first version of a method according to theinvention,

FIG. 2 shows a diagram of a second version of a method according to theinvention,

FIG. 3 shows a diagram of a third version of a method according to theinvention, and

FIG. 4 shows a diagram of an optical recording device according to theinvention.

FIG. 1 shows a control signal 1 for controlling the power of theradiation beam. When a mark is recorded, the control signal 1, and hencethe power of the radiation beam, is first set from bottom power levelP_(B) to intermediate power level P_(i) and then is set to the writepower P_(W) during the first portion 2 of the write irradiation period 3and subsequently it is set to the elevated write power level P_(E)during the second portion 4 of the write irradiation period 3.Afterwards, the control signal 1, and hence the power of the radiationbeam, is set again to the write power P_(W) during the third portion 5of the write irradiation period 3 and then it is set to bottom powerlevel P_(B).

FIG. 2 shows a control signal 6 for controlling the power of theradiation beam. When a mark is recorded, the control signal 6, and hencethe power of the radiation beam, is first set from bottom power levelP_(B) to intermediate power level P_(i) and then is set to the elevatedwrite power P_(E) during the first portion 7 of the write irradiationperiod 8. Afterwards, the control signal 6, and hence the power of theradiation beam, is set to the write power P_(W) during the secondportion 9 of the write irradiation period 8 and then it is set to bottompower level P_(B).

FIG. 3 shows a control signal 10 for controlling the power of theradiation beam. When a mark is recorded, the control signal 10, andhence the power of the radiation beam, is first set from bottom powerlevel P_(B) to the write power P_(W) during the first portion 11 of thewrite irradiation period 12. Afterwards, the control signal 10, andhence the power of the radiation beam, is set to the elevated writepower P_(E) during the second portion 13 of the write irradiation period12 and then it is set to bottom power level P_(B).

FIG. 4 shows an optical recording device according to the invention forrecording a data signal 20 on the recording surface 301 of a disc-shapedoptical record carrier. The optical record carrier is rotated around itscenter by a motor 34. A radiation beam 32 is generated by a radiationsource 31 and focused onto the recording surface 301 by a lens 33.

The data signal 20 is connected to control means 60. A current source 61within the control means 60 has four outputs, A, B, C and D. Output Aprovides a current which, when fed to the radiation source 31 through acontrol signal S_(C), will produce the radiation beam 32 having a writepower level P_(W). Likewise, outputs B, C and D provide currentsresulting in the elevated write power level P_(E), the bottom powerlevel P_(B) and the intermediate power level P_(i), respectively. Thecurrent of each output A, B, C and D can be selected by a switch-unit 62within the control means 60. The switch-unit 62 is operated by a patterngenerator 63 controlled by the data signal 20. The pattern generator 63transforms the data signal 20 into a control signal 23.

The control means 60 also comprise setting means 64 for setting thecurrent of the outputs B and D of the current source 61. The current ofoutput B of the current source 61 is set in dependence on the length ofthe duration of elevated power level periods. Thus, by setting thecurrent of output B, the elevated write power level is set in dependenceon the length of the mark to be recorded. The current of output D of thecurrent source 61 is set in dependence on duration of the bottom powerperiod preceding the write power period, thus, by setting the current ofoutput D, the intermediate power level is set in dependence on thelength of the land preceding the mark to be recorded.

FIG. 3 shows an embodiment of an optical recording device according tothe invention. However, it will be apparent to those skilled in the artthat embodiments of an optical recording device using more power levelscan be realized by adding further outputs to the current source 61 andby extending the switch-unit 62. Moreover, it will be apparent that asingle output B, respectively D, of the current source 61 providing avarying current can, as an alternative, be replaced by several outputs,each providing a different current, while the setting means 64 selectthe appropriate output for setting the elevated write power level andthe intermediate power level, respectively, at any time.

1. An optical record carrier recording method for forming marks andlands by applying a radiation beam to a recording surface of an opticalrecord carrier, the marks having a time length of nT, where T representsthe time length of one period of a reference clock in a data signal andn represents a predetermined natural number, where the radiation beamfor each mark to be recorded is first set to an intermediate powerirradiation level, the intermediate power irradiation level being higherthan a bottom power irradiation level and lower than a write powerirradiation level, where the intermediate power irradiation level is setin accordance with a time length of the preceding bottom powerirradiation period, characterized in that after the intermediate powerirradiation period, the radiation beam for each mark to be recorded isset to the write power irradiation level during a first and a thirdportions of a write irradiation period, whereas the radiation beam foreach mark to be recorded is set to an elevated write power level duringa second portion of the write irradiation period, where the elevatedwrite power level is higher than the write power level, and where boththe elevated write power level and the duration of the second portion ofwrite irradiation period are being set in accordance with a time lengthof a mark to be recorded.
 2. An optical record carrier recording methodfor forming marks and lands by applying a radiation beam to a recordingsurface of an optical record carrier, the marks having a time length ofnT, where T represents the time length of one period of a referenceclock in a data signal and n represents a predetermined natural number,where the radiation beam for each mark to be recorded is first set to anintermediate power irradiation level, the intermediate power irradiationlevel being higher than a bottom power irradiation level and lower thana write power irradiation level, where the intermediate powerirradiation level is set in accordance with a time length of thepreceding bottom power irradiation period, characterized in that afterthe intermediate power irradiation period, the radiation beam for eachmark to be recorded is set to an elevated write power irradiation levelduring a first portion of a write irradiation period, whereas theradiation beam for each mark to be recorded is set to the write powerlevel during a second portion of the write irradiation period, where theelevated write power level is higher than the write power level, andwhere both the elevated write power level and the duration of the firstportion of write irradiation period are being set in accordance with atime length of the mark to be recorded.
 3. An optical record carrierrecording method as claimed in claim 1, characterized in that theelevated write power level for recording a mark having a time length nTis set to be higher than the elevated write power level for recording amark having a time length (n+1)T.
 4. An optical record carrier recordingmethod as claimed in claim 1, where n equals 2, characterized in thatthe elevated write power level is set to be lower than 2.0 times thewrite power level.
 5. An optical record carrier recording method asclaimed in claim 1, where n equals 3, characterized in that the elevatedwrite power level is set to be lower than 1.7 times the write powerlevel.
 6. An optical record carrier recording method as claimed in claim1, where n equals 4, characterized in that the elevated write powerlevel is set to be lower than 1.5 times the write power level.
 7. Anoptical record carrier recording method as claimed in claim 1, where nis larger than 4, characterized in that the elevated write power levelis set to be lower than 1.4 times the write power level.
 8. An opticalrecord carrier recording method for forming marks and lands by applyinga radiation beam to a recording surface of an optical record carrier,the marks having a time length of nT, where T represents the time lengthof one period of a reference clock in a data signal and n represents apredetermined natural number smaller than 3, where the radiation beamfor each mark to be recorded is first set to an intermediate powerirradiation level, the intermediate power irradiation level being higherthan a bottom power irradiation level and lower than a write powerirradiation level, where the intermediate power irradiation level is setin accordance with a time length of the preceding bottom powerirradiation period, characterized in that after the intermediate powerirradiation period the radiation beam for each mark to be recorded isset to the write power irradiation level during a first portion of awrite irradiation period, whereas the radiation beam for each mark to berecorded is set to an elevated write power level during a second portionof the write irradiation period, where the elevated write power level ishigher than the write power level.
 9. An optical record carrierrecording method as claimed in claim 8, characterized in that theelevated write power level is set to be lower than 2.0 times the writepower level.
 10. An optical record carrier recording method as claimedin claim 1, where the duration of the length of a preceding bottom powerirradiation period is smaller than 2T, characterized in that theintermediate power irradiation level is set to be lower than 0.5 timesthe write power level.
 11. An optical record carrier recording method asclaimed in claim 1, where the duration of the length of a precedingbottom power irradiation period is equal to 3T, characterized in thatthe intermediate power irradiation level is set to be within the rangefrom 0.3 to 0.8 times the write power level.
 12. An optical recordcarrier recording method as claimed in claim 1, where the duration ofthe length of a preceding bottom power irradiation period is equal to4T, characterized in that the intermediate power irradiation level isset to be within the range from 0.4 to 0.9 times the write power level.13. An optical record carrier recording method as claimed in claim 1,where the duration of the length of a preceding bottom power irradiationperiod is greater than 4T, characterized in that the intermediate powerirradiation level is set to be greater than 0.5 times the write powerlevel.
 14. An optical recording device for recording data in the form ofmarks and lands on a recording surface of an optical record carrier byirradiating the recording surface by means of a radiation beam, thedevice comprising a radiation source for providing the radiation beamand control means for controlling the power of the radiation beam suchas that it has at least one write power level capable of forming a markduring a write power irradiation period and that it has at least onebottom power level incapable of forming a mark during a bottom powerirradiation period and that is has at least one intermediate power levelbeing higher than bottom power level and lower than write power levelwhere the control means are operative to set the intermediate powerirradiation level in accordance with a time length of the precedingbottom power irradiation period, characterized in that the control meansare operative to control the power of the radiation beam after theintermediate power irradiation period such that it has the write powerlevel capable of forming a mark during a first and a third portions of awrite irradiation period, and the elevated write power level capable offorming a mark during a second portion of a write irradiation period,where the elevated write power level is higher than the write powerlevel, and where both the elevated write power level and the duration ofthe second portion of write irradiation period are being set inaccordance with a time length of a mark to be recorded.
 15. An opticalrecording device for recording data in the form of marks and lands on arecording surface of an optical record carrier by irradiating therecording surface by means of a radiation beam, the device comprising aradiation source for providing the radiation beam and control means forcontrolling the power of the radiation beam such as that it has at leastone write power level capable of forming a mark during a write powerirradiation period and that it has at least one bottom power levelincapable of forming a mark during a bottom power irradiation period andthat is has at least one intermediate power level being higher thanbottom power level and lower than write power level where control meansare operative to set the intermediate power irradiation level inaccordance with a time length of the preceding bottom power irradiationperiod, characterized in that the control means are operative to controlthe power of the radiation beam after the intermediate power irradiationperiod such that it has the elevated write power level capable offorming a mark during a first portion of a write irradiation period, andthe write power level capable of forming a mark during a second portionof a write irradiation period, where the elevated write power level ishigher than the write power level, and where both the elevated writepower level and the duration of the first portion of write irradiationperiod are being set in accordance with a time length of a mark to berecorded.
 16. An optical recording device for recording data in the formof marks and lands on a recording surface of an optical record carrierby irradiating the recording surface by means of a radiation beam, thedevice comprising a radiation source for providing the radiation beamand control means for controlling the power of the radiation beam suchas that it has at least one write power level capable of forming a markof a length of 2T during a write power irradiation period, where Trepresents the time length of one period of a reference clock in datasignal and that it has at least one bottom power level incapable offorming a mark during a bottom power irradiation period and that is hasat least one intermediate power level being higher than bottom powerlevel and lower than write power level where the control means areoperative to set the intermediate power irradiation level in accordancewith a time length of the preceding bottom power irradiation period,characterized in that the control means are operative to control thepower of the radiation beam after the intermediate power irradiationperiod such that it has the write power level capable of forming a markduring a first portion of a write irradiation period, and the elevatedwrite power level capable of forming a mark during a second portion of awrite irradiation period, and where the elevated write power level ishigher than the write power level.
 17. An optical record carrier forrecording data in the form of marks and lands by irradiating itsrecording surface by means of a radiation beam characterized in thatintermediate power level parameters, elevated write power levelparameters and parameters denoting duration of elevated write powerlevel portion of write irradiation period are recorded on the opticalrecord carrier.